I expect several Choir folk will have listened to Building a Library, which was one of those dialogue-overview affairs.
I wonder if anyone shares my thought that the Madrigali need to be delivered with a certain amount of Italianate passion and expressiveness? Two of the available performing groups have countertenors on top and both seem to produce rather tame, precious accounts. It is generally thought that Gesualdo would have used female singers (3 Ladies of Ferrara, and all that) and for me the only group that came close was The Consort of Musicke.
Books 4 and 5 do get quite tricky, and I wonder if some of our well-known recording choirs have been unwilling to dip their toes in the water?